BETWEEN THE VISCOSITY OF LIQUIDS AND THELR CHEMICAL NATURE. 513 
Butyric Acid. CH 3 .(CHo) 2 .COOH. 
From Dr, Perkin. It was found to boil at 1G I°'5. n — 29°'5, t = 28° (emergent 
column). Bai’. 759'5 millims. Corrected and reduced b.p. = t6^°‘02, 
The observations for viscosity gave :— 
Left limb. 
Right limb. 
Temp, 
Press. 
Corr. 
Temp. 
Press. 
Corr. 
0 
3-26 
128-62 
-000016 
■021257 
0 
3-16 
128-54 
■000016 
■021.306 
18-01 
128-44 
-000021 
■015907 
18-03 
128-42 
■000021 
■015921 
31-84 
128-81 
-000027 
■012624 
31-82 
12806 
■000027 
■012643 
44-53 
128-83 
-000032 
■010474 
44-45 
128-73 
■000032 
■010498 
59-40 
128-89 
-000038 
■008587 
59-.39 
128-78 
■000038 
■008604 
73-25 
128-25 
-000044 
■007277 
73-47 
128-20 
■000044 
■007268 
86-56 
128-20 
■000050 
■006274 
86-54 
128-12 
■000050 
■006276 
101-49 
128-45 
■000057 
■005367 
101-60 
128-40 
■000058 
■005368 
115-42 
128-49 
■000065 
■004689 
115-06 
128-48 
■000064 
■004705 
130-29 
128-29 
•000073 
■004075 
1.30-23 
128-27 
■000072 
■004087 
144-97 
128-23 
■000081 
■003583 
144-97 
1-28-15 
■000081 
■003579 
155-78 
128-22 
■000087 
■003267 
L55-74 
128-12 
■000087 
■003266 
The relative density of butyric acid has been frequently determined, and there 
seems little reason to prefer any one value to the exclusion of the others from among 
the concordant observations of Delfts, Pierre, Mendeleeff, Lanuolt, Linnemann, 
and Bruhl. We have, therefore, adopted the mean of the different results, namely, 
d{0°l0°) = 0'9786, which is almost identical with the observations of Landolt and 
Brqhl, 
For the thermal expansion we have taken the means of the very concordant obser¬ 
vations of Pierre (‘Annales de Chimie et de Phys.,’ (3), 31, 127), and Zander 
= -003207 17.2 (calculated) = '008338 
= 155°'76 t .2 (from curve) — 6 P'87, 
195-7G5 
~ (94'4G2 + 93305 ’ 
which gives the following calculated values r— 
(‘Annalen,’ 234, p. 91). 
Taking 
= -021282 
Q = 3°'21 
we obtain the formula 
3 u 
MDCCCXCIV.—A. 
